wurlitzer 412 lightweight cartridge conversion questions

[tpignaloni]

I will soon have my 412 delivered. i was wondering what would be needed if i wanted to convert the magnetic cartridge to a lightweight ceramic one? are there aftermarket kits? i know the volume control and tone components will need to be changed, but is this documented somewhere? i also suppose i need an adaptor for a  new cartridge in the tonearm. any help, links to suppliers to purchase parts needed will be helpful.

[Hildegard]

You could use an adapter plate which holds a ceramic cartridge, e.g. Astatic 51-2 resp. nowadays Pfanstiehl P51-2.
If you are in USA, Victory Glass offers those: victoryglass.com/product/part-number-10-2273/
If there is a counterweight in the back of the (Bearclaw)tonearm it needs to get removed.
The orignal cartridge was magnetic if I am right. So input stage f amp needs a modification too.
of ourse the tonearm pressure needs to be re-adjusted well afterwards and might become quite tricky.

Hildegard

[Startgroove]

There are several things to address when converting to a lightweight ceramic cartridge. First, I would strongly recommend avoiding gutting the original volume control unit. Some people do that to get a little more volume, and there are kits available for replacing the original components. Again, I would stay away from that method, no matter how convincing the seller might be about doing it. The reason being that this method does not correct the big difference in tonal output from the magnetic vs ceramic pick ups. Ceramic cartridges typically drop off the low tones from about 300 Hz down. The result being that the sound is tinny and without bass. The best way, in my opinion, is to find an original Kit 87 pre-amp (made by Wurlitzer back in the day for just such a conversion). They show up on Ebay now and then and run anywhere from 25 to 65 dollars. It will then need to be recapped. There are other pre-amps which were available at the time, Jacobs and Wico as examples. They all work the same, increase the bass and match the output impedance of the ceramic pick up to the input impedance of the amplifier. I've done this conversion several times and I'm here to say the tonal response and volume are amazingly beautiful!
Yet, there is more. The tone-arm with ceramic cartridge is very light tracking and therefore has a hard time staying in the groove when in the eccentric reject grooves. Modifications to the reject system will solve this skipping problem. One way, not the best, but the easiest, is to replace the reject wire with one that has a shallower ramp. The other is to install an electric reject. The later was available back in the day, but they seem to be extremely difficult to find and usually need to be rebuilt. Another way is to build one from scratch. A coil and switch and bracketry is all that is required.  As an alternative, if you can find one, is to use the electric reject system out of a Wurlitzer 1100 or 1080A.